Books by Ernst Mayr

Reviews

of books by Ernst Mayr

ERNST MAYR (1904-2005) was Alexander Agassiz Professor of Zoology, Emeritus, at the Museum of Contemporary Biology, Harvard University. Ernst Mayr's career as a classical biologist had profound influence on his writing on the development of the history and philosophy of biology and its unifying theme -- Charles Darwin's theory (theories) of evolution. Mayr studied in Germany and emigrated to the United States during the 1940s. Mayr was a genuine scientist and thinker and his work and publications have helped shape the modern synthesis of evolutionary theory and away from Darwinism. His profound knowledge about the origins of evolutionary ideas is reflected in Mayr's many books. As he wrote in the foreword to the German edition of 'The Growth of Biological Thought' (Die Entwicklung der biologischen Gedankenwelt; Springer; 1984), he saw his contribution in philosophy of biology mainly in overcoming and eliminating the gap between science and philosophy by teaching each others knowledge.

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The Growth of Biological Thought

by Ernst Mayr
Harvard University Press, 1982, 1985

Written with the intention to write a history of biology, Mayr presents the history of scientific and philosophical thinking about the evolution of living organisms. In a general introduction he presents a philosophy of science, and the ever changing way of thinking and perceiving that allows new discoveries from the ancient Greeks to modern molecular biology. To understand evolution is really to understand the diversity of life. It is the latter that is available to biologists, complemented by archeological and palaeontological findings corroborating the time frame of evolutionary processes. A taxonomic (classification) system is the fundament of every theory of evolution. Classification schemes, however, are truly artificial systems and of course subject to change and adjustment. They are arbitrary to the extend to which we think about reality. Using the wrong classification will never lead to the correct theory of evolution and understanding of the actual historical path that evolution took. Darwin's theory of natural selection provides the framework from which every current biological inquire is derived. A classification that does not adhere to this model of evolution, is truly arbitrary and does not reflect biological reality.

The book is structured in three parts as mentioned in the subtitle: diversity of life, evolution, variation and inheritance. The latter is really an account of 20th Century biology and how the general notion of Mendelian inheritance has changed into the concept of genes and the chemical basis of inheritance (DNA).

December 30, 1999 / © Lukas K. Buehler / go back to Book Review Home

Toward a New Philosophy of Biology

by Ernst Mayr
Harvard University Press, 1988

This volume, published six years after 'The Growth of Biological Thought', is an abridged version of the latter, does not require a college degree in biology, leaves out much of the historical presentation of the idea of evolution of life, and focuses more sharply on the philosophy of biology. In its preface, Mayr sounds like Edward O. Wilson, the intellectual father of sociobiology and author of Consilience, The Unity of Knowledge, when he writes:

'Since the scientific Revolution, the philosophy of science has been characterized by an almost exclusive reliance on logic, mathematics, and the laws of physics. But in recent years we have witnessed a laudable state of ferment in the field. This unrest stems mainly from the growing realization that any sound philosophy of science must do justice to the living world as well as to the physical one.'

However, Mayr claims that it is too early to come to a firm philosophy of biology. Too many aspects are not fully understood, and while Darwin's theory of evolution lied the ground work of such a philosophy, it is important to realize the limitations of today's biological knowledge. Unlike quantum mechanics and the general theory of relativity, biology is not done with its inquires into the nature of life. Mayr rightfully criticizes the overly enthusiastic reliance on logic, mathematics and laws of physics in biology. Many fields are still descriptive, although molecular biology and biochemistry have made great advances in uncovering the microscopic, i.e., the physico-chemical laws that apply to the behavior of biological macromolecules. But many questions in medicine (Cancer), immunology, (self-non self), or neurobiology (consciousness, psychology) are phenomenological rather than hard science. Mayr uses the term vagueness. Thus any philosophy of biology deals with concepts rather than laws of nature: speciation, adaptation, or macroevolution. The book is organized in chapters along these conceptual lines.

What Makes Biology Unique?

by Ernst Mayr
Cambridge University Press, 2004

In his latest book published at the age of 100 and just a few months before his death on February 3, 2005, Ernst Mayr summarized his major thoughts on the importance of biology as an independent science, different from chemistry and physics and even deserving of its own philosophy, a philosophy of biology distinct from current philosophies of science that are mainly oriented on modern physics. His core belief was that reductionist understanding of reality is particularly misleading in biology, since lower level functions cannot explain the functions of more complex organization of matter as are always found in living things. The irreducible complexity of organisms is now being studied by systems biology and characterizing complexity as unique to the biological sciences will be one of the most important tasks of biology in the 21st century.

With this book Mayr demands a philosophy of biology that treats biology as an autonomous science, distinct in many respects from the dominant hard science (Wissenschaft) of physics and chemistry, and similar to the soft science of the humanities (Geisteswissenschaften), particularly history. Mayr distinguishes two aspects of biology: functional biology that relies on experimental approaches of the hard science and asks how something happens, and evolutionary biology that is driven by asking why and uses methodologies familiar to the humanities like historical narratives and comparison, for instance in anatomy and genomics (studying similarities).

Mayr outlines a systematic approach to validate his postulate of an autonomy of biology. This outline has three components. First, it must be understood that some erroneous principles that until Darwin's theory of evolution were thought to be essential to explain life have been successfully eliminated from biological thinking. They include vitalism and cosmic teleology, concepts that both require nonphysical forces or supernatural explanations in order to distinguish animate from inanimate matter. Vitalism and cosmic teleology (progression towards final perfection) have been replaced by the conceptual framework of physiology (teleomatic),development (teleonomic or program directed), behavior (purposive), and evolution (adaptive features), exactly where physics has the least to offer in terms of explanatory power (except for physiological states).

Second, it is necessary to understand which physical principles do not apply to biology. They include essentialism, determinism, reductionism, and general applicability of law's of nature. All four approaches may be suitable to functional biology, but cannot be used to explain evolution. For most of biology, there are no laws and logic based on math as Mayr poignantly refers to Darwin's treatise on the origin of species, a scientific work utterly devoid of physical laws and mathematical formalism.

Third, the absence of laws makes biology unique and different from the physical sciences, yet biology very much depends on concepts, e.g. selection, populations, phylogeny, imprinting, and development. The uniqueness of biology is found in the complexity of macromolecules, cells, organisms, populations, and ecosystems. It is also found in the crucial element of chance and random changes without which evolution cannot be explained.

This small book is true marvel that will engage the reader interested in the philosophy of science or better yet biology. Mayr was the preeminent evolutionary biologists of the 20th century and a great historian (see 'The Growth of Biological Thought' above) and reading his thoughts certainly gives an authoritative insight into biology as a science. There is a problem here and there, however, when he refers to specific aspects of physics. Mayr correctly states that organisms do not violate the laws of physics (no vitalism), but that these laws are not enough to explain life. So far, so good. Mayr takes his goal of distinguishing biology from physics too far in some instances. I want to mention a few. He emphatically claims several times that 20th century physics (relativity, quantum mechanics) has contributed nothing or little to biology. This may be true for evolutionary biology, but functional biology has greatly benefited from the work of physicists. The discovery of X-rays is the foundation of high resolution structure analysis without which no DNA double helix structure would be available and thus no information about the genetic code or mechanisms of inheritance, a critical component of functional biology that lends support to evolutionary biology. Mayr may not have known that Einstein is not just famous for his theory of relativity, but also for giving a theoretical explanation of Brownian motion, one of the few physical phenomena where chance is crucial and is an essential ingredient in the behavior of all cellular structures. He also claims that entropy is not applicable to biological systems since the latter are open systems. Mayr is simple wrong here. Entropy is a crucial element in understanding the formation of complex structures (self-assembly) in the absence of a vis vitalis.